Electrical connector for rotary drum



Oct. 9, 1962 w. MESSERLI ELECTRICAL CONNECTOR FOR ROTARY DRUM Filed July17, 1958 United States Patent Office p, 3,058,082 Patented Oct. 9, 1,962

3,058,082 ELECTRICAL CONNECTOR FOR ROTARY DRUM Walter Messerli, 3Quartierstrasse, Wettingeu, Aargau, Switzerland Filed July 17, 1958,Ser. No. 749,252 1 Claim. (Cl. 3398) The present invention relates to adevice for the supply of electric current to rotatably mounted bodies,in particular to bodies of rotation to be welded, having a conductordetachably to be connected to the rotatably mounted body and to beattached to an external current source.

Known devices of this kind connected the cable effecting the supply ofcurrent directly to the rotatably mounted body, e.g. to a cylindricaldrum to be welded. Upon turning the drum as required for the welding thecable was twisted about itself and the entanglement formed had to beunraveled from time to time, which had the consequences of earlydestruction of the cable and of repeated loss of time.

It is the primary object of the present invention to provide a device ofthe kind referred to wherein the aforesaid disadvantages are overcomeand any entangling f the supply cable is safely prevented.

With this and other objects in view, as will become apparent later fromthe following specification and accompanying drawing, I provide a devicefor the supply of electric current to rotatably mounted bodies and moreparticularly to bodies of rotation to be welded, comprising incombination: a conductor detachably connected to the said rotatablymounted body, a conductor connectable to an external source of current,a disc consisting of electrically conductive material connected to oneof the said conductors, a bolt arranged co-axially to the said disc andconnected to the other one of the said conductors, and resilient contactmembers mounted on the said bolt so as to be restrained from rotatingrelative thereto and to electrically contact and resiliently abut thesaid disc.

These and other features of my said invention will be clearly understoodfrom the following description of a preferred embodiment thereof givenby way of example with reference to the accompanying drawing, in which:

FIG. 1 is a diagrammatic perspective view of a general arrangement,

FIG. 2 is a longitudinal part-section of the particular device on alarger scale.

Referring now to the drawing,

In FIG. 1 a support structure of conventional type for a drum .1 to bewelded is indicated by two rollers 2 only. As well known, the drum 1 isset in rotation on such rollers 2 in order to produce weld seams runningin a circumferential direction. The supply of current to the drum 1 iseffected by a cable 3 which is connected by means of a clamp 4 to aconductor 5 as well as, by components of the device to be describedlater, to the conductor 6 screwed to the drum 1 at 6a. The conductor 6may be attached to any desired or convenient point of the rotary drum 1,for instance to an eccentrically positioned tab 1a projecting from theend wall of the drum.

These aforesaid components of the device which prevents the cable fromgetting entangled, comprise a disc 7 connected electrically conductivelyand preferably fixedly to the conductor 5, which disc consists of amaterial having good electrical conductivity and at the same timesufficient resistance to mechanical wear. As suitable for this purpose abronze alloy has been found which is known under the proprietory name ofMallory.

The disc 7 has a central bore and forms a partition wall in a roundcasing 8 into which enters a bolt 9 conductively connected to theconductor 6.

As will be seen form FIG. 2 the reduced forward end 9a of this bolt 9penetrates a central bore '10 of the disc 7, which is supported on thebolt end 9 by oppositely arranged shoulders on two abutting aperturedcircular plates 13 and 14. In order to pass the electric current fromthe conductor 5 to the conductor 6, resilient contact members 11 aremounted on the bolt 9. These conductive contact members are connected toand restrained rotationally relative to the bolt 9 by means of washers15 and a nut 12. They abut resiliently with their outer margins on thedisc 7 and since they contact the same electrically conductively allover their circumferences a large contact area is established, which isalso maintained constantly during operation.

The contact members 11 have preferably a dished shape. They are mountedon the bolt 9 pre-stressed between the washers 15 in such a manner thatthey resiliently bear on the disc 7.

In the embodiment according to FIG. 2, the contact members are arrangedsubstantially symmetrically to the disc 7. In certain circumstances itmay, however suflice to provide the same at one side of said isc only.

The device described, which has proved to be very effective in practice,assures a good and sufficient contact area between the relativelymovable contact members and therefore a safe supply of current, andprevents safely any entangling of the current supply cable 3, since thesame can no longer be twisted when turning the drum 1.

While I have herein described and illustrated in the accompanyingdrawing what may be considered a typical and particularly usefulembodiment of my said invention, I wish it to be understood that I donot limit myself to the particular details and dimensions shown anddescribed; for obvious modifications will occur to a person skilled inthe art.

What I claim as my invention and desire to secure by Letters Patent, is:

In combination with a rotary body to be seam-welded, a cylindricalcasing, a radially extending member connected thereto having a connectoradapted to be electrically connected to a source of electrical energy, apartition wall in said casing located between the ends thereof andextending radially inward, a threaded bolt member adapted to beconnected to the end of said rotary body having a reduced threaded endportion extending through an opening in an end wall of said casing andprojecting through a central opening in said partition, a series ofdish-shaped contact members arranged in spaced relation on the reducedend of said threaded bolt member and disposed on opposite sides of saidpartition with their peripheral edges yieldingly urged into frictionalcontact with the radial walls of sad partition, and a retaining nutthreaded on said reduced end of said threaded bolt member to retain saiddish-shaped contact members in position, said partition wall beingrotatably mounted on said threaded bolt member and forming the solesupport of said housing with respect to said threaded bolt member.

References Cited in the file of this patent UNITED STATES PATENTS966,520 Bumiller Aug. 9, 1910 4 Martus July 21, 1925 Trogner June M,1930 Baum Feb. 11, 1941 Raymond July 5, 1949 Solari July 14, 1953 FavreJuly 14, 1959 FOREIGN PATENTS France Nov. 14, 1949

